Web Release of Digital Content for “Yamazaki Bridge” (Kubosō Memorial Museum of Arts, Izumi)

“Yamazaki Bridge” Digital Content – Top Page

Image Comparison Page

Engi text (Inscription) Page

　The Tokyo National Research Institute for Cultural Properties (TOBUNKEN) concluded a memorandum of understanding for joint research with the Kubosō Memorial Museum of Arts, Izumi in 2024 (Reiwa 6). Under this collaboration, research has been conducted on works in the museum’s collection, and a research meeting on the painting “Yamazaki Bridge” was held in September 2025 (Reiwa 7). (https://www.tobunken.go.jp/materials/katudo/2403901.html))

　With the aim of making the results of the optical investigation of “Yamazaki Bridge” widely available, we created digital content for the work and have now released it as an open-access resource. The site provides explanations in both Japanese and English regarding the work and the research methods used. Users can freely zoom in and out while comparing high-resolution color images of the painting with near-infrared and fluorescence images.

　In many historical artworks, the surface of the painting becomes difficult to see due to aging, making it challenging to identify depicted elements and fine details with the naked eye. In the near-infrared images, however, ink line drawings can be observed with remarkable clarity, while fluorescence images reveal features such as areas of infill silk carried out during past restorations and differences in coloring materials. In addition, for the engi text (inscription) located at the bottom of the painting, we developed photographic methods and image-processing techniques designed to make the characters easier to discern. Previous studies have relied primarily on the text in an accompanying document dating to the late Edo period. Now that the characters on the painting’s surface can be more readily examined, it has become possible to undertake more in-depth analysis. Further advances in research are therefore anticipated.

　We invite you to explore the pictorial space of this work and experience the atmosphere of the Kamakura period that it evokes.

Public Access to the Digital Content for the Honpō-ji Temple Lotus Sutra Mandala Painting

The Kazaire Memorial Service at Honpō-ji Temple

Digital content screen

　The Lotus Sutra Mandala scrolls preserved at Honpō-ji Temple, an ancient temple in Toyama City, Toyama Prefecture, are a unique and large-scale example consisting of a set of 22 large-format panels that visually illustrate the contents of the 28 chapters of the Lotus Sutra. Believed to have been created between the first and third years of the Karyaku era (1326–1328) at the end of the Kamakura period, they are also valued for their confirmed date of origin. Every year on August 6, during the Kazaire Memorial Service, the Lotus Sutra Mandala is hung inside the main hall of the temple and explained to the congregation, offering a tangible sense of how this deeply rooted local ritual has been passed down to the present day.

　The Tokyo National Research Institute for Cultural Properties (TOBUNKEN) received a donation of high-resolution image data from Dr. HARAGUCHI Shizuko (Nara University), who has long been engaged in research on the Honpō-ji Lotus Sutra Mandala, captured during her research. Using this data, the Institute created digital content featuring color and infrared images of all 22 panels of the Lotus Sutra Mandala, as well as images of accompanying materials. We began limited public access to this content within the TOBUNKEN Library in March 2026.
（https://www.tobunken.go.jp/joho/japanese/library/library_collection/index.html#digitalcontents）

　Although the Hokke-kyō Mandala Painting at Honpō-ji Temple is an extremely valuable example of its kind, it has rarely been exhibited as a complete set due to the large number of panels involved. Furthermore, because the illustrations in published books are limited in scope, it had not been possible to examine the details sufficiently. The digital content released on this occasion allows users to zoom in on specific areas of the painting and compare them with infrared images. We hope this will serve as an opportunity for many people to discover the rich world of the Lotus Sutra Mandala.

　For information on accessing the digital content, please visit the TOBUNKEN website:
https://www.tobunken.go.jp/joho/japanese/library/library_collection/index.html

We would like to express our sincere gratitude to Honpō-ji Temple for their cooperation and support in making this available to the public.

*Affiliations listed are as of that time.

The 10th Seminar Held by the Department of Art Research, Archives and Information Systems

The Seminar

　At the 10th seminar held by the Department of Art, Research, Archives and Information Systems at the Tokyo National Research Institute for Cultural Properties (TOBUNKEN) on March 16, 2026, research presentations were given by Ms.MAIZAWA Rei (Department of Art, Research, Archives and Information Systems) and Dr. OKU Takeo (Musashino Art University).

　First,　Ms.　MAIZAWA presented a report titled “Research Report: The Bronze Standing Statue of the Eleven-Faced Kannon at Hase-dera Temple,” providing an overview of the Eleven-Faced Kannon statue at Hase-dera Temple in Nara. The Hase-dera temple statue is a gilt-bronze statue of the Buddha created during the Kamakura period and is believed to be a standing statue of the Eleven-Faced Kannon modeled after the principal image of Hase-dera Temple. Ms. MAIZAWA examined the statue’s style and iconography and pointed out that it exhibits unique characteristics in its casting techniques.

　Following Ms. MAIZAWA’s presentation, Dr. OKU delivered a research presentation titled “A Reexamination of the Statues of the Thousand-Armed Kannon and the Twenty-Eight Attendants in the Main Hall of Rengeō-in.” It is well known that the Main Hall of Rengeō-in Temple (Sanjūsangendō) in Kyoto was originally built in 1164 but was destroyed by a major fire during the Kamakura period and rebuilt in 1266. Regarding the Twenty-Eight Attendants—the retinue of the principal image of the Thousand-Armed Kannon—Dr. OKU first noted that, based on an entry in the Sankai-ki (a diary from the Heian period), these figures were present at the time of the temple’s founding. He further pointed out that many of the extant statues were created during the Heian period at the time of the temple’s founding, and that even those statues created anew during the Kamakura period generally followed the style of the original statues from the founding era. He argued that the dates of creation for the Twenty-Eight Attendants statues could be determined based not only on their artistic style but also on the characteristics of their production techniques; his argument was highly persuasive, drawing on the insights gained from his many years of experience in the field of cultural property restoration. He also discussed the possibility that the statue of Basūsen among the Twenty-Eight Attendants reflects a devotion to Mount Wutai in China, and touched upon the original vision of Retired Emperor Goshirakawa-in at the time of the temple’s founding. Dr. OKU’s presentation made a significant contribution to the history of research on the Twenty-Eight Attendants of Rengeōin, and following the presentation, participants engaged in a lively exchange of views, making it a highly productive seminar.

Public Access to a List of Photographic Films from the YANAGISAWA Taka Collection

Examples of the films in the YANAGISAWA collection

A database screen

　Ms. YANAGISAWA Taka (1926–2003), who served for many years at the Tokyo National Research Institute for Cultural Properties (TOBUNKEN), remained active until the end of her life as a leading scholar in the history of Japanese Buddhist painting, and through her meticulous and keen observational skills, authored numerous papers that form the foundation of the field’s scholarly history. After Ms. YANAGISAWA’s passing, most of the large collection of photographic film stored at her home was donated to the Aesthetics and Science of Arts Laboratory at Keio University, where she had taught; however, a portion of the film—believed to have been taken in connection with her work at TOBUNKEN—was accepted by the Department of Art Research, Archives and Information Systems.

　Now, more than 20 years after Ms. YANAGISAWA’s passing, we have completed a digitization of the entire collection of 1,297 items—comprising positive film shot during surveys conducted both domestically and abroad, as well as collected prints—and published a list of them on the TOBUNKEN website: https://www.tobunken.go.jp/materials/yanagisawa_film.

　The positive film contains footage shot with infrared video cameras, which were still rare at the time, making it an invaluable resource for understanding the history of TOBUNKEN, which incorporated scientific methods into cultural property surveys from the early postwar period. The digitized images are available for viewing in the TOBUNKEN Library. Please visit our website for details on how to access them.
https://www.tobunken.go.jp/joho/english/library/application/application_image.html

Public Access of Materials from the Former Collection of Teizo Suganuma

Examples of the materials in the SUGANUMA collection at the Library

A look at the material organization process

　Mr. SUGANUMA Teizō (1900–1993) worked at the Tokyo National Research Institute for Cultural Properties (TOBUNKEN) before becoming a professor at Keio University, where he devoted himself to the study of early modern Japanese painting, particularly literati painting, and authored numerous papers and books. The materials he collected during his tenure at the university were long kept in a research room at Keio University, and were donated to TOBUNKEN in 2023 by Mr. KAWAI Masatomo (Professor Emeritus, Keio University), who took over the Keio laboratory. Most of the materials consist of mounted paper prints; in addition to early modern paintings—primarily literati paintings—the collection includes photographic materials of screen paintings, architecture, and sculpture gathered by Mr. NISHIKAWA Shinji (1920–1999), a leading authority on the history of Japanese sculpture and a former professor at Keio University.

　With the cooperation of Mr. YASUNAGA Takuyo (Seijō University), the Department of Art Research, Archives and Information Systems has been working to organize and catalog the materials in its collection, and has now made catalogs for all materials and digital images of the microfilms available on the TOBUNKEN website: https://www.tobunken.go.jp/materials/suganuma_print. In particular, the collection of literati paintings and screen paintings includes works of which the current whereabouts are unknown, as well as works that have changed hands since their original creation; as such, this collection is an invaluable resource for contemporary research on these works. The actual materials are stored in cabinets in the TOBUNKEN Library and are available for viewing on-site. Please click here for information on how to use the Library.

On Oil painting Production in the Early Showa Period as seen in Handwritten Materials of KIMURA Shohachi: The 11th Seminar Held by the Department of Art Research, Archives and Information Systems for the 2025 Fiscal Year

Scene from the seminar

　Materials in the collection of the Tokyo National Research Institute for Cultural Properties (TOBUNKEN) are open to researchers and broadly used, but in fact, there are not many items that shed light on the process of their collection itself. In this seminar, focusing on “Handwritten Materials of KIMURA Shohachi” in the collection of TOBUNKEN, Mr. TANAKA Jun (Visiting Researcher, Director of the Okawa Museum of Art), who was in charge of the collection of those materials while in office, and Ms. ARAI Yumi (Associate Professor, National Institute of Technology, Nara College), who has been conducting research on the materials based on literary studies in recent years, took the stage to elucidate the significance of those materials and report on the results of their research.

　First, in his presentation titled “On the History of Collecting Materials of KIMURA Shohachi in TOBUNKEN,” Mr. TANAKA reported on how he had been collecting, transcribing, and researching those materials in collaboration with other institutions for nearly three decades, and introduced the testimony of a former collector of those materials who had interacted with KIMURA, in which he stated that KIMURA was a compulsive notetaker who kept a notebook with him in every room at home and wrote in it randomly.

　Next, in her talk titled “On Issues Related to the Making of “Gathering for Pan” ― focusing on a “Production Note by KIMURA Shohachi from Showa 5th to Showa 11th” in the collection of TOBUNKEN,” Ms. ARAI focused on diaries from the early Showa period among those materials, sorted out the situation of materials in a complex chronological order, and discussed descriptions related to painting production, focusing on one of his representative works, the oil painting “Gathering for Pan,” 1928, in the collection of the Kitano Museum of Art.　

　The image of the “random notetaker” as described by Mr. TANAKA, and KIMURA’s writing style as described by Ms. ARAI, in which the contents were written at different times in the same diary, were matched perfectly. Guided by such episodes, opinions were actively exchanged on the human image of KIMURA while looking at the real materials during the Q&A session.

　This seminar was a valuable opportunity for researchers of art history and literature studies to come together to exchange opinions on situations of the early Showa period through documents of a painter.

Release of the “Database of Photographic Materials Formerly Held by Kokka-sha”

Image of a screen from the “Database of Photographic Materials Formerly Held by Kokka-sha.”

　The Department of Art Research, Archives and Information Systems has opened a database for public access called the “Database of Photographic Materials Formerly Held by Kokka-sha.”

　Kokka is a scholarly journal devoted to Japanese and East Asian art, founded in 1889 by figures such as OKAKURA Tenshin and TAKAHASHI Kenzo. It remains one of the oldest continuously published art journals in the world. Established at a time when Japanese art faced the risk of dispersal, the journal sought to introduce its value to a global audience and to promote the preservation of cultural heritage. The title Kokka (“The Flower of the Nation”) is said to derive from the founding statement: “Art is the essence of a nation.”

　The collection of photographic materials formerly held by Kokka-sha (the publisher of Kokka) comprises images accumulated and preserved over many decades through the editorial process of Kokka, which has spanned more than 130 years. From its inception, the journal has placed a strong emphasis on the quality of visual reproductions, employing techniques such as collotype printing by leading photographer OGAWA Kazumasa, as well as woodblock prints produced by master craftsmen. These materials are grounded in records generated through rigorous editorial practices and constitute an important foundation for art historical research.

　To facilitate scholarly use of these resources, a portion of the materials donated by Kokka-sha has been made publicly available through this database. Emphasizing timely access and the sharing of research materials, the database will be expanded and updated on an ongoing basis.

　https://www.tobunken.go.jp/materials/kokka-sha_photo

The Work of Critic SOEDA Tatsurei— The 9th Seminar Held by the Department of Art Research, Archives and Information Systems

SAKOUCHI Yuji delivering his presentation

A scene from the discussion

　In the study of modern and contemporary art, while it is natural to focus on the artists who create the works, it is also important to investigate and examine the critics who evaluate these artists and works, and pass our knowledge of these artists and their works on to future generations through the writings of these critics.

　At the Seminar Held by the Department of Art Research, Archives and Information Systems held on March 4, two researchers gave presentations focusing on SOEDA Tatsurei (1888–1971), who left behind numerous works, including A History of Struggles in the Japanese Art World (published in 1924), Appreciation of Nanga and Literati Painting (published in 1934), and Hanko and Fuko (published in 1955).

　In his presentation, “SOEDA Tatsurei and His Materials,” Mr. SAKOUCHI Yuji (Kosugi Hoan Museum of Art, Nikko) shed light on SOEDA’s life and achievements, which had previously been largely unknown. This was followed by a presentation by Mr. HORI Yoshio (Fukushima Prefectural Museum of Art) titled “SOEDA Tatsurei and His Interactions with Japanese Painters from the East and West as Seen in Correspondence,” in which he introduced letters addressed to SOEDA from Japanese painters from both the eastern and western regions—including KANASHIMA Keika, TSUCHIDA Bakusen, DOMOTO Insho, KATAYAMA Nanpu, and SAKAI Sanyo—thereby shedding light on a facet of their interactions.

　The research presented by these two scholars is based on an investigation of materials passed down through the SOEDA family, conducted with the support of the Idemitsu Museum of Arts. The seminar was attended by Ms. INO Azusa (Kawagoe City Art Museum) and Mr. TANABE Ken (Kosugi Hoan Museum of Art, Nikko), who participated in this research, as well as Ms. ENAKA-SOEDA Satoko (Professor Emerita, Showa Women’s University), who is SOEDA Tatsurei’s granddaughter. During the discussion following the presentations, opinions were exchanged regarding SOEDA’s place in art history and the future utilization of the surviving collection of materials, interspersed with recollections from Professor ENAKA.

Introduction of a Single-Sided H-NMR System and its First Application to Non-Destructive Moisture Measurement in Brick Masonry Structures

On-site measurements of brick masonry in a building

Preliminary measurements in the laboratory

　In FY2025, the Center for Conservation Science introduced a single-sided H-NMR system. Moisture contained within porous materials can induce various deterioration phenomena, including physical damage caused by salt crystallization and freezing, deformation due to expansion and contraction, and biological degradation such as mold growth. Therefore, understanding the moisture condition within materials is a key factor in assessing deterioration risks and determining appropriate conservation strategies.

　Single-sided H-NMR detects NMR signals from hydrogen nuclei in water by applying a magnetic field generated by the instrument. By analyzing the intensity and temporal variation of these signals, it is possible to evaluate both the moisture content and the mobility of hydrogen in water within the material.

　In March 2026, an on-site investigation was conducted on a brick masonry building where deterioration of the wall surfaces had progressed due to salt crystallization associated with the capillary rise of seawater. This survey represents the first field application of the system since its introduction. Non-destructive measurements of moisture content profiles in the direction of depth were carried out. Conventional non-destructive methods are often limited to surface measurements or require smooth surfaces, making it difficult to obtain information about the internal condition of deteriorated walls. In contrast, this method enables the acquisition of depth-resolved moisture distribution profiles regardless of surface condition.

　This study was conducted as part of a collaborative research project involving the Tokyo National Research Institute for Cultural Properties (TOBUNKEN), Kyoto University, Nagoya University, and the Nara National Research Institute for Cultural Properties (NABUNKEN), focusing on material treatments and environmental control strategies to mitigate salt weathering in brick masonry structures.

　In the future, we aim not only to quantify moisture content but also to extend this technique to the non-destructive evaluation of material properties necessary for developing appropriate conservation measures. Furthermore, we plan to expand its application to a wider range of materials and cultural heritage objects.　

Promotion of Research on the Conservation and Utilization of Cultural Heritage through International Collaboration

Administration of the Archaeological Park of Pompeii

National Archaeological Museum of Naples

　The Japan Center for International Cooperation in Conservation conducts international collaborative research focusing primarily on immovable cultural heritage, including wall paintings, from both theoretical frameworks and practical techniques related to conservation and utilization. Through these efforts, the Center aims to strengthen the foundation for improving the standards of conservation, restoration, and maintenance management, while also promoting international cooperation projects for cultural heritage protection that make use of these research outcomes.

　From February 24 to March 13, 2026, a research visit to Italy was conducted, during which consultations were held with researchers from the University of Urbino, the University of Florence, and the National Research Council of Italy (CNR). The main agenda of these discussions was to identify current challenges related to conservation and restoration materials and to examine research directions that could contribute to their improvement. Through these consultations, it was confirmed that all participating institutions share a common awareness of these issues, and an agreement was reached to advance concrete research under a framework of international collaboration.

　In addition, during visits to the National Archaeological Museum of Naples and the Archaeological Park of Pompeii, the current state of conservation and restoration of Roman wall paintings and stucco decorations was surveyed. At the same time, exchanges of views were conducted with local researchers regarding the challenges of existing methodologies and possibilities for their improvement. As a result, wall paintings and stucco decorations under the management of the Archaeological Park have been made available as research subjects for this project, and cooperation has been secured for research aimed at advancing conservation and restoration techniques.

　Going forward, as part of this research initiative, Roman wall paintings and stucco decorations will serve as the primary focus, and in collaboration with the institutions consulted during this visit, efforts will be made to advance material studies and to systematize conservation and restoration techniques. This initiative is expected to play a significant role in establishing a foundation for the deepening and practical development of international collaboration in the field of cultural heritage conservation. Furthermore, the outcomes of this work will be applied to the practice of conservation, restoration, and maintenance of cultural heritage both in Japan and abroad, with the aim of contributing to the sustainable protection and utilization of cultural heritage in various regions.